OT: 10 megajoule Rail gun

[Martin Riddle]

<http://www.foxnews.com/story/0,2933,327205,00.html>

 

[MooseFET]

<http://www.foxnews.com/story/0,2933,327205,00.html>

From the look of the sparks, the gun is eroding its self. Some of
them look like iron sparks but the object appeared to be aluminum.
They also have a problem with the projectile trying to rotate in the
gun. I would not want to be anywhere near the gun when they try to
ramp the power up.

I wonder if it really is 10MJ or if that is just the offical line.
Back in WW2 all ships could do 23 Knots if you asked how fast a ship
could go.

 

[Phil Hobbs]

From the look of the sparks, the gun is eroding its self. Some of
them look like iron sparks but the object appeared to be aluminum.
They also have a problem with the projectile trying to rotate in the
gun. I would not want to be anywhere near the gun when they try to
ramp the power up.

I wonder if it really is 10MJ or if that is just the offical line.
Back in WW2 all ships could do 23 Knots if you asked how fast a ship
could go.

A 5-inch gun shoots a projectile weighing about 70 lbs, with about 18
lbs of HE. At 10 MJ, the muzzle velocity is just over 800 m/s, which
isn't so far off from a normal artillery muzzle velocity. If they can
really reach 32 MJ, that would be a beast.


Cheers,

Phil Hobbs

 

[_]

From the look of the sparks, the gun is eroding its self. Some of
them look like iron sparks but the object appeared to be aluminum.
They also have a problem with the projectile trying to rotate in the
gun. I would not want to be anywhere near the gun when they try to
ramp the power up.

I wonder if it really is 10MJ or if that is just the offical line.
Back in WW2 all ships could do 23 Knots if you asked how fast a ship
could go.

That's little low.

Many warships would easily do much better, years before the outbreak of
hostilities.

 

[amdx]

<http://www.foxnews.com/story/0,2933,327205,00.html>

What program did you use to play the video?

 

[MooseFET]

That's little low.

Many warships would easily do much better, years before the outbreak of
hostilities.

23 Knots was the story you'd get if you asked. It was a number that
sounded good and news reporters even back then weren't technical
enough to know that it was just a story.

 

[MooseFET]

What program did you use to play the video?

I used "xine"

 

[Fred Bloggs]

23 Knots was the story you'd get if you asked. It was a number that
sounded good and news reporters even back then weren't technical
enough to know that it was just a story.

But Courant had already worked out the determination of top speed
capability of warships using bow wake angles at a known speed as
collected from aerial reconnaissance photography...

 

[[email protected]]

<http://www.foxnews.com/story/0,2933,327205,00.html>

What a tremendous waste of resources. Obviously this thing is designed
to funnel grant money and military-corporate welfare money into
someone's pockets.
While they fire one projectile at a cost of millions, the dastardly
enemy opens fire with a cheap and reliable Gatling gun and rains down
thousands of projectiles.

 

[Tim Williams]

While they fire one projectile at a cost of millions, the dastardly
enemy opens fire with a cheap and reliable Gatling gun and rains down
thousands of projectiles.

Which...harmlessly plink off the hull. Try again.

Now, a sixteen inch Iowa class naval gun, that's something to think
about...

Tim

 

[[email protected]]

Which...harmlessly plink off the hull. Try again.

Really? An Avenger "tank buster" will fire shells that bounce off the
hull?
http://en.wikipedia.org/wiki/GAU-8_Avenger

Now, a sixteen inch Iowa class naval gun, that's something to think
about...

Again, cheap, proven, reliable technology that you can pump out by the
hundreds and fire hundreds of times.
Each projectile provides its own power, "densified" at the explosives
plant.
If the rail gun fails, you can't fire any projectiles anymore.

 

[Jim Yanik]

[email protected] wrote in [email protected]:

Really? An Avenger "tank buster" will fire shells that bounce off the
hull?
http://en.wikipedia.org/wiki/GAU-8_Avenger

which could not get NEAR a warship,as SAMs and AA Artillery(AAA) would
obliterate them. Those Gatlings only have a limited range,WELL inside a
ship's defensive screen.Phalanx or Goalkeeper would tear the A-10s apart,if
the SAMs didn't.
(and that also neglects comabt air patrols the enemy would have to fight
through.An A-10 could NOT fight thru.)

Also,the GAU-8 had the A-10 BUILT around it,and it's a old,SLOW
aircraft,very vulnerable to todays air defenses.
There are NO other planes that carry the GAU-8.
None that could carry it,AFAIK.

nobody knows how to use those 16" guns anymore,the projectiles/powder are
old and scrapped(along with the entire Iowa class BBs)
In fact,no US ship today carries any gun larger than 5".
A 155mm gun(6") is being considered for a new type of ship.
No 16" naval gun could be fitted on today's warships.

Again, cheap, proven, reliable technology that you can pump out by the
hundreds and fire hundreds of times.
Each projectile provides its own power, "densified" at the explosives
plant.
If the rail gun fails, you can't fire any projectiles anymore.

rail guns will have a much greater effective range.
100's of miles vs ~3/4 mile.
they also may fire terminally-guided projectiles.(at Mach5)


Big clue;it's not just the guns/weapons,it's the entire SYSTEM that
matters,AC or warship.

 

[donald]

[email protected] wrote in [email protected]:



which could not get NEAR a warship,as SAMs and AA Artillery(AAA) would
obliterate them. Those Gatlings only have a limited range,WELL inside a
ship's defensive screen.Phalanx or Goalkeeper would tear the A-10s apart,if
the SAMs didn't.
(and that also neglects comabt air patrols the enemy would have to fight
through.An A-10 could NOT fight thru.)

Also,the GAU-8 had the A-10 BUILT around it,and it's a old,SLOW
aircraft,very vulnerable to todays air defenses.
There are NO other planes that carry the GAU-8.
None that could carry it,AFAIK.


nobody knows how to use those 16" guns anymore,the projectiles/powder are
old and scrapped(along with the entire Iowa class BBs)
In fact,no US ship today carries any gun larger than 5".
A 155mm gun(6") is being considered for a new type of ship.
No 16" naval gun could be fitted on today's warships.


rail guns will have a much greater effective range.
100's of miles vs ~3/4 mile.
they also may fire terminally-guided projectiles.(at Mach5)


Big clue;it's not just the guns/weapons,it's the entire SYSTEM that
matters,AC or warship.

This argument is NOT about weapon systems. Its about politics.

Its about "how can I keep money coming into my district".

The old "jobs in my state" vs "jobs in your state" politics.

donald

 

[z]

<http://www.foxnews.com/story/0,2933,327205,00.html>

"Because the railgun uses electricity and not gunpowder to fire
projectiles, it eliminates the possibility of explosions on ships."

What do they use for power, then, that can match gunpowder? Middle of
a battle: "Captain, batteries are running low again. Time to
requisition the crew's Energizers?"

 

[z]

Which...harmlessly plink off the hull.  Try again.

Now, a sixteen inch Iowa class naval gun, that's something to think
about...

or a couple of jihadis in a rowboat filled with fertilizer and fuel
oil in the middle of the night. haven't forgotten the cole already,
have we?

 

[Martin Griffith]

What program did you use to play the video?

Is this the one?
http://www.theregister.co.uk/2008/02/01/us_navy_railgun_test_video_success/
or here as well

martin

 

[[email protected]]

A 5-inch gun shoots a projectile weighing about 70 lbs, with about 18
lbs of HE. At 10 MJ, the muzzle velocity is just over 800 m/s, which
isn't so far off from a normal artillery muzzle velocity. If they can

Ah but how much money is transferred to contractors and uranium
suppliers?
If each ship now requires extra nukes just to power the latest toys,
how much uranium is left to power civilian power stations?
What happens to yellowcake prices, and who gets to keep burning coal?
I wonder which country has an estimated 200 years of coal reserves?

really reach 32 MJ, that would be a beast.

Cheers,

Phil Hobbs

How fast does air resistance go up?

 

[[email protected]]

Big clue;it's not just the guns/weapons,it's the entire SYSTEM that
matters,AC or warship.

--
Jim Yanik
jyanik
at
kua.net

Here's a bigger clue, Jim:
http://www.theregister.co.uk/2008/02/01/us_navy_railgun_test_video_success/
"The Office of Naval Research are hoping that they can scale up their
electric cannon to 64-megajoule levels"

Hoping.

"at present railgun barrels only have a life of three or four shots"

So while all these nerds are hoping about getting their toy to reach 6
times the energy level of the test shot, probably leading to a barrel
life of *one*, the enemy launches a civilian airliner with fanatics on
board...

Wrong target, Jim. The rules have changed, and the old guard keeps
coming up with old solutions.
Yawn. More corporate welfare to keep the defense trough filled, and
keep the civilians appeased.

 

[MooseFET]

But Courant had already worked out the determination of top speed
capability of warships using bow wake angles at a known speed as
collected from aerial reconnaissance photography...

That tells you how fast the ship was going at the time not the max
speed it could do.

You are arguing "mere facts" in a situation where the facts aren't
what is important. Having something that sounded good for the
reporters was what mattered. Reporters don't like "I won't tell you".

 

[Corbomite Carrie]

"Because the railgun uses electricity and not gunpowder to fire
projectiles, it eliminates the possibility of explosions on ships."

What do they use for power, then, that can match gunpowder? Middle of
a battle: "Captain, batteries are running low again. Time to
requisition the crew's Energizers?"

You don't know much about electrical power or batteries OR charging
systems. Obviously.